From: dave.long@linaro.org (David Long)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v11 8/9] arm64: Add kernel return probes support (kretprobes)
Date: Mon, 21 Mar 2016 09:33:51 -0400 [thread overview]
Message-ID: <56EFF83F.7040906@linaro.org> (raw)
In-Reply-To: <50399556C9727B4D88A595C8584AAB37B4E504AA@GSjpTKYDCembx32.service.hitachi.net>
On 03/17/2016 08:58 AM, ???? / HIRAMATU?MASAMI wrote:
>> From: ???? / HIRAMATU?MASAMI [mailto:masami.hiramatsu.pt at hitachi.com]
>>
>> Hi,
>>
>>> From: Sandeepa Prabhu <sandeepa.s.prabhu@gmail.com>
>>>
>>> The pre-handler of this special 'trampoline' kprobe executes the return
>>> probe handler functions and restores original return address in ELR_EL1.
>>> This way the saved pt_regs still hold the original register context to be
>>> carried back to the probed kernel function.
>>
>> This patch seems not well separated.
>>
>>> diff --git a/arch/arm64/kernel/kprobes.c b/arch/arm64/kernel/kprobes.c
>>> index bd3f233..13d3333 100644
>>> --- a/arch/arm64/kernel/kprobes.c
>>> +++ b/arch/arm64/kernel/kprobes.c
>>
>> [snip]
>>
>>> +void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
>>> + struct pt_regs *regs)
>>> +{
>>> + ri->ret_addr = (kprobe_opcode_t *)regs->regs[30];
>>> +
>>> + /* replace return addr (x30) with trampoline */
>>> + regs->regs[30] = (long)&kretprobe_trampoline;
>>
>> So, where is the kretprobe_trampoline? It seems that function is
>> defined in other patch.
>>
>>> +}
>>> +
>>> +int __kprobes arch_trampoline_kprobe(struct kprobe *p)
>>> +{
>>> + return 0;
>>> }
>>
>> And what this function is for??
>
> Ah, sorry, this was my fault. Yes, this function is required.
> But this implementation also means there is an asm-based trampoline
> function which should be included in this patch.
>
> David, could you tell me the repository which I can get the latest
> version of this series? I'd like to see the whole code of kprobes/arm64.
>
> Thank you,
>
It can be found in:
http://git.linaro.org/people/dave.long/linux.git
...in the kprobes64-v11 branch.
Thanks,
-dl
next prev parent reply other threads:[~2016-03-21 13:33 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-09 5:32 [PATCH v11 0/9] arm64: Add kernel probes (kprobes) support David Long
2016-03-09 5:32 ` [PATCH v11 1/9] arm64: Add HAVE_REGS_AND_STACK_ACCESS_API feature David Long
2016-03-11 18:07 ` James Morse
2016-03-18 13:06 ` David Long
2016-03-15 11:04 ` Marc Zyngier
2016-03-21 7:08 ` David Long
2016-03-09 5:32 ` [PATCH v11 2/9] arm64: Add more test functions to insn.c David Long
2016-03-09 5:32 ` [PATCH v11 3/9] arm64: add copy_to/from_user to kprobes blacklist David Long
2016-03-15 18:47 ` James Morse
2016-03-16 5:43 ` Pratyush Anand
2016-03-16 10:27 ` James Morse
2016-03-17 7:57 ` Pratyush Anand
2016-03-18 13:29 ` Pratyush Anand
2016-03-18 14:02 ` James Morse
2016-03-18 14:43 ` Pratyush Anand
2016-03-18 18:12 ` James Morse
2016-03-21 5:17 ` Pratyush Anand
2016-03-21 14:52 ` Will Deacon
2016-03-22 16:51 ` Pratyush Anand
2016-03-17 12:04 ` 平松雅巳 / HIRAMATU，MASAMI
2016-03-09 5:32 ` [PATCH v11 4/9] arm64: add conditional instruction simulation support David Long
2016-03-13 12:09 ` Marc Zyngier
2016-03-14 4:04 ` Pratyush Anand
2016-03-14 7:38 ` Marc Zyngier
2016-03-21 8:35 ` David Long
2016-03-09 5:32 ` [PATCH v11 5/9] arm64: Kprobes with single stepping support David Long
2016-04-20 1:29 ` Li Bin
2016-03-09 5:32 ` [PATCH v11 6/9] arm64: kprobes instruction simulation support David Long
2016-03-12 3:56 ` Marc Zyngier
2016-03-21 9:39 ` David Long
2016-03-09 5:32 ` [PATCH v11 7/9] arm64: Add trampoline code for kretprobes David Long
2016-03-13 13:52 ` Marc Zyngier
2016-03-21 13:30 ` David Long
2016-03-09 5:32 ` [PATCH v11 8/9] arm64: Add kernel return probes support (kretprobes) David Long
2016-03-17 12:22 ` 平松雅巳 / HIRAMATU，MASAMI
2016-03-17 12:58 ` 平松雅巳 / HIRAMATU，MASAMI
2016-03-21 13:33 ` David Long [this message]
2016-03-09 5:32 ` [PATCH v11 9/9] kprobes: Add arm64 case in kprobe example module David Long
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